When I plan a new pollinator garden or change an existing garden, I start choosing plants for the easiest season first — fall. Goldenrods and asters are the stars and workhorses of the fall pollinator garden.
In late summer and fall, both plants are covered in beautiful blooms, as well as a wide variety of pollinators attracted by abundant nectar and high-protein pollen. In winter, Juncos and remaining Goldfinches eat the seeds. To read more about the special roles of these plants, see the Wild Seeds Project’s article The Beauty and Pollinator Benefits of Asters and Goldenrods.
It’s a shame that goldenrods aren’t used more in gardens here, like they are in Europe. One big reason it’s ignored is the myth that it cause allergies; its pollen is large and sticky to facilitate insect pollination, so it doesn’t blow around. Instead, ragweed is the culprit, which has fine, light pollen because the plant is wind-pollinated. For more information, read the Nature Web article Fall Allergies? Don’t Blame Goldenrod!
Another reason goldenrods are rarely used in gardens is because common Canada Goldenrod is an aggressive spreader. There are actually many other kinds of goldenrod that are well-suited for gardens.
For sun, there are many possibilities. I really like the umbellifer-clusters of flowers on Ohio Goldenrod and Stiff Goldenrod. ‘Fireworks’ Rough Goldenrod is my latest-bloomer and attracts lots of bees and migrating Monarchs well into September and October.
To my surprise, there are also some lovely goldenrods for shadier spots. Zigzag goldenrod is my absolute favourite. It’s wand-like stems are covered in golden stars and insects. Watch my YouTube video of the remarkable insect activity on one of my Zigzag Goldenrod plants. This plant grows in dry, part-shade to shade, and is even fragrant. What’s not to love? Bluestem Goldenrod has a arching habit and is another plant I grow in part-shade. While Zigzag Goldenrod spreads slowly becoming a ground-cover, Bluestem Goldenrod remains in a clump.
More recently, I tried growing Silverod from seed. Believe it or not, it has creamy-white flowers, instead of bright yellow. It blooms earlier than my other goldenrods and has an upright shape. Beaux Arbres Native Plants sells seeds and plants.
Smooth aster is a great purple-blue aster for sun, and is popular with various bees in my garden. Its yellow flower centres combine beautifully with goldenrod. It also looks lovely with the fall leaves of native shrubs.
Some of my favourite pictures of asters are from Le Jardin Plume, in France. Romantic clouds of asters and feathery grasses dot the fall gardens. The Ottawa Public Library has their book Le jardin plume: comme un jeu avec la nature.
Heart-leaved aster grows in part-shade and has smaller blue flowers.
White wood aster also grows in part-shade and has many small white flowers with yellow centres.
Annuals for pollinators in fall
In the fall, migrating Monarchs and Painted Lady butterflies particularly enjoy Mexican tithonia and Brazilian verbena to fuel up for their long journeys.
Watch a video of Monarchs and Painted Ladies on my Mexican tithonia patch in September 2017. This was an unusual congregation of butterflies waiting for the winds to change direction to facilitate their flight south. You can read about this unusual phenomenon in the CBC Montreal article Wondering where all those butterflies came from? What a spectacular sight!